Clot ablation using focused ultrasound and thrombolytic drugs to treat chronic deep vein thrombosis

(Top panel) PCI of histotripsy-induced bubble clouds withing a porcine clot. The histotripsy pulse is propagating along the axial dimension (from left to right) in the image. The artifact along the elevational direction of the histotripsy transducer occurs because of the elongated point spread function in the direction normal to the face of the linear array. (Bottom panel) The temporally averaged PCI amplitude as a function of the axial dimension at a fixed elevational location (dotted and dashed line in top panel). The boundaries of the lumen are denoted in green, and the clot boundaries are noted in blue.

Deep vein thrombosis is a debilitating condition that can require rapid intervention to prevent amputation of the affected limb or death. The current interventional approaches are not effective for older, chronic thrombi, characteristic of those found in deep vein thrombosis. Histotripsy is a novel form of therapeutic ultrasound that employs the mechanical action of oscillating cavitation bubbles to ablate thrombi. Preliminary data from Dr. Bader demonstrate that the thrombolytic recombinant tissue plasminogen activator acts synergistically with histotripsy pulses to provide enhanced thrombolysis in highly retracted venous clots. Further studies will elucidate the efficacy and potential risks of histotripsy to ablate venous thrombosis, and provide new information to assist the development of targeted ablation methods to improve thrombolysis in the treatment of currently intractable deep vein thrombosis.